Catheter ablation of atrial fibrillation in patients with left bundle branch block.

BACKGROUND: Left bundle branch block (LBBB) and atrial fibrillation (AF) are commonly coexisting conditions. The impact of LBBB on catheter ablation of AF has not been well determined. This study aims to explore the long-term outcomes of patients with AF and LBBB after catheter ablation. METHODS: Forty-two patients with LBBB of 11,752 patients who underwent catheter ablation of AF from 2011 to 2020 were enrolled as LBBB group. After propensity score matching in a 1:4 ratio, 168 AF patients without LBBB were enrolled as non-LBBB group. Late recurrence and a composite endpoint of stroke, all-cause mortality, and cardiovascular hospitalization were compared between the two groups. RESULTS: Late recurrence rate was significantly higher in the LBBB group than that in the non-LBBB group (54.8% vs. 31.5%, p = .034). Multivariate analysis showed that LBBB was an independent risk factor for late recurrence after catheter ablation of AF (hazard ratio [HR] 2.19, 95% confidence interval [CI] 1.09-4.40, p = .031). LBBB group was also associated with a significantly higher incidence of the composite endpoint (21.4% vs. 6.5%, HR 3.98, 95% CI 1.64-9.64, p = .002). CONCLUSIONS: LBBB was associated with a higher risk for late recurrence and a higher incidence of composite endpoint in the patients underwent catheter ablation.

Risk Factors for Left Ventricular Thrombus Formation in Patients with Dilated Cardiomyopathy.

BACKGROUND: Left ventricular thrombus (LVT) is a common complication of dilated cardiomyopathy (DCM), causing morbidity and mortality. METHODS: This study retrospectively analyzed patients with DCM from January 2002 to August 2020 in Beijing Anzhen Hospital. Clinical characteristics were compared between the LVT group and the age and sex 1:4 matched with the LVT absent group. The receiver operator characteristic (ROC) curve was plotted to evaluate the diagnostic value of D-dimer predicting LVT occurrence in DCM. RESULTS: A total of 3,134 patients were screened, and LVT was detected in 72 (2.3%) patients on echocardiography. The patients with LVT had higher D-dimer, fibrinogen, and lower systolic blood pressure than those without LVT. The ejection fraction (EF) was lower and left ventricular end-systolic diameter was larger in the LVT group. Severe mitral regurgitation (MR) was more common in the LVT absent groups. The prevalence of atrial fibrillation was lower in the LVT group. The ROC curve analysis yielded an optimal cut-off value of 444 ng/mL DDU (D-dimer units) for D-dimer to predict the presence of LVT. Multivariable binary logistic regression analysis revealed that EF (OR = 0.90, 95% CI = 0.86-0.95), severe MR (OR = 0.19, 95% CI = 0.08-0.48), and D-dimer level (OR = 15.4, 95% CI = 7.58-31.4) were independently associated with LVT formation. CONCLUSION: This study suggested that elevated D-dimer levels (>444 ng/mL DDU) and reduced EF were independently associated with increased risk of LVT formation. Severe MR could decrease the incidence of LVT.

Comparison of prognosis and outcomes of catheter ablation versus drug therapy in patients with atrial fibrillation and stable coronary artery disease: A prospective propensity-score matched cohort study.

BACKGROUND: Atrial fibrillation (AF) and stable coronary artery disease (SCAD) frequently coexist. HYPOTHESIS: To investigate the prognosis of catheter ablation versus drug therapy in patients with AF and SCAD. METHODS: In total, 25 512 patients with AF in the Chinese AF Registry between 2011 and 2019 were screened for SCAD. 815 patients with AF and SCAD underwent catheter ablation therapy were matched with patients by drug therapy in a 1:1 ratio. Primary end point was composite of thromboembolism, coronary events, major bleeding, and all-cause death. The secondary endpoints were each component of the primary endpoint and AF recurrence. RESULTS: Over a median follow-up of 45 ± 23 months, the patients in the catheter ablation group had a higher AF recurrence-free rate (53.50% vs. 18.41%, p < .01). In multivariate analysis, there was no significant difference between the strategy of catheter ablation and drug therapy in primary composite end point (adjusted HR 074, 95%CI 0.54-1.002, p = .0519). However, catheter ablation was associated with fewer all-cause death independently (adjusted HR 0.36, 95%CI 0.22-0.59, p < .01). In subgroup analysis, catheter ablation was an independent risk factor for all-cause death in the high-stroke risk group (adjusted HR 0.39, 95%CI 0.23-0.64, p < .01), not in the low-medium risk group (adjusted HR 0.17, 95%CI 0.01-2.04, p = .17). CONCLUSIONS: In the patients with AF and SCAD, catheter ablation was not independently associated with the primary composite endpoint compared with drug therapy. However, catheter ablation was an independent protective factor of all-cause death.

Modifications of the Langendorff Method for Simultaneous Isolation of Atrial and Ventricular Myocytes from Adult Mice.

A single cardiomyocyte is a vital tool in the cellular and subcellular level studies of cardiac biology and diseases as a fundamental unit of contraction and electrical activity. Hence, isolating viable, high-quality cardiomyocytes from the heart is the initial and most crucial experimental step. Comparing the various protocols for isolating the cardiomyocytes of adult mice, the Langendorff retrograde perfusion is the most successful and reproducible method reported in the literature, especially for isolating ventricular myocytes. However, isolating quality atrial myocytes from the perfused heart remains challenging, and few successful isolation reports are available. Solving this complicated problem is extremely important because apart from ventricular disease, atrial disease accounts for a large part of heart diseases. Therefore, further investigations on the cellular level to reveal the mechanisms are warranted. In this paper, a protocol based on the Langendorff retrograde perfusion method is introduced and some modifications in the depth of aorta cannulation and the steps that may affect the digestion process to isolate atrial and ventricular myocytes were simultaneously made. Moreover, the isolated cardiomyocytes are confirmed to be amenable to patch clamp investigation.

New-Onset Atrial Fibrillation and Adverse In-Hospital Outcome in Patients with Acute Pulmonary Embolism.

Atrial fibrillation (AF) can be secondary to acute pulmonary embolism (PE). This study aimed to investigate the prognostic impact of new-onset AF on patients with acute PE. In this study, 4,288 consecutive patients who were diagnosed with acute PE were retrospectively screened. In total, 77 patients with acute PE and new-onset AF were analyzed. Another 154 acute PE patients without AF were selected as the age- and sex-matched control group. Adverse in-hospital outcome comprised one of the following conditions: all-cause death, endotracheal intubation, cardiopulmonary resuscitation, and intravenous catecholamine therapy. The patients with new-onset AF had higher prevalence of congestive heart failure, higher simplified PE severity index (sPESI), higher creatinine, and larger left atrium diameter. The incidences of adverse in-hospital outcomes were 10.4 and 2.6% in patients with new-onset AF and no AF, respectively (p = 0.02). Patients with sPESI ≥ 1 had higher incidence of adverse in-hospital outcomes than those with sPESI = 0 (9.4 vs. 0.9%, p < 0.01). The area under the receiver operating characteristic curve of sPESI and sPESI + AF (adding 1 point for new-onset AF) scores in assessing the adverse in-hospital outcome were 0.80 (95% confidence interval [CI]: 0.68-0.93) and 0.84 (95% CI: 0.72-0.96), respectively. In multivariable analysis, sPESI ≥ 1 (odds ratio, 8.88; 95% CI: 1.10-72.07; p = 0.04) was an independent predictor of adverse in-hospital outcome. However, new-onset AF was not an independent predictor. In the population studied, sPESI is an independent predictor of adverse in-hospital outcomes, whereas new-onset AF following acute PE is not, but it may add predictive value to sPESI.

Relationship Between Ablation Lesion Size Estimated by Ablation Index and Different Ablation Settings-an Ex Vivo Porcine Heart Study.

This study aimed to verify the reliability of ablation index (AI) for ablation lesion estimating with different settings for radiofrequency (RF) parameters: power, impedance, contact angles, irrigation rate, temperature of irrigation saline, and irrigation solution. RF ablations (N = 66) were performed on ex vivo porcine left ventricle submerged in 37 °C saline. The aforementioned ablation parameters were changed to measure whether the size of the ablation lesion was consistent at a fixed AI value of 500. The maximum lesion diameter (r = - 0.631, P = 0.028), depth (r = - 0.896, P < 0.001), and volume (r = - 0.745, P < 0.005) were significantly reduced with an increase of the impedance. The lesion depth (P < 0.05) and the lesion volume (P < 0.05) were significantly larger with glucose irrigation than saline irrigation. In conclusion, at a fixed AI value, impedance and irrigation solution have impact on the ablation lesions, which could affect the accuracy of AI formula to estimate ablation lesion size. Graphical abstract.

Atrial tachycardia eliminated at the ventricular side in patients with congenitally corrected transposition of the great arteries: Electrophysiological findings and anatomical concerns.

BACKGROUND: The unique malformation of congenitally corrected transposition of the great arteries (cc-TGA) makes the pulmonary outflow tract (POT) a possible origin of atrial tachycardia (AT). OBJECTIVE: The purpose of this study was to investigate the mapping characteristics of ATs successfully ablated at the POT in patients with cc-TGA. METHODS: Patients with cc-TGA with AT eliminated at the POT were analyzed. Activation mapping of the atria and POT was performed under the guidance of a 3-dimensional electroanatomic mapping system. The activation pattern of these chambers was investigated, with the local activation time (LAT; using coronary sinus ostium as a reference) of the earliest activation site (EAS) being compared. RESULTS: AT eliminated at the POT was documented in 5 of 6 patients with cc-TGA. The EAS was at the right anteroseptal region with a LAT of 33 (21-120) ms in the right atrium and at the septal wall with a comparable LAT (26, 47, and 26 ms; P = .604) in the left atrium. The EAS of the POT was in the vicinity of the left-facing pulmonary sinus cusp in 3 cases and the nonfacing pulmonary sinus cusp in 2 cases, with a LAT of 106 (28-134) ms preceding both atria. Ablation at this site successfully eliminated AT in all 5 cases. CONCLUSION: AT arising adjacent to the POT is not an uncommon tachycardia in patients with situs solitus-type cc-TGA and can be safely eliminated by ablation targeting the EAS in the POT.

Depolarization and repolarization parameters on ECG predict recurrence after atrial fibrillation ablation in patients with hypertrophic cardiomyopathy.

INTRODUCTION: The outcomes of atrial fibrillation (AF) ablation remain suboptimal. It is important to identify which AF patients will most likely benefit from ablation and who are more likely to show treatment failure, especially in those with structural heart disease such as hypertrophic cardiomyopathy (HCM). METHODS AND RESULTS: We enrolled 120 HCM patients who underwent primary AF ablation (48 with persistent AF). Preprocedural QTc was measured and corrected using the Bazett's formula, and the distribution of fragmentation of the QRS complex (fQRS) was recorded. Arrhythmia recurrence was defined as any kind of documented atrial tachyarrhythmia of more than 30 seconds. Overall, arrhythmia recurrence occurred in 69 patients after 13.4 months' follow-up. fQRS was present in 71 (59.17%) patients and was most commonly (81.69%) observed in the inferior leads. QTc more than 448 ms could predict arrhythmia recurrence with a sensitivity of 68.1% and specificity of 68.6%. Patients with QTc more than 448 ms (hazard ratio [HR]: 1.982; 95% confidence interval [CI]: 1.155-3.402; P = .013) or those with fQRS+ (HR: 1.922; 95% CI: 1.151-3.210; P = .012) were at an increased risk of recurrence. A combination of fQRS+ and QTc more than 448 ms was superior to fQRS or QTc alone in predicting arrhythmia recurrence. CONCLUSION: In patients with HCM undergoing AF ablation, QTc prolongation, specifically >448 ms, and presence of fQRS are independent risk factors for arrhythmia recurrence at follow-up. The combination of these two parameters has greater predictive value and would help to identify patients who are at the highest risk of procedural failure.

Female Sex as a Risk Factor for Ischemic Stroke and Systemic Embolism in Chinese Patients With Atrial Fibrillation: A Report From the China-AF Study.

Background Previous studies have provided conflicting results as to whether women are at higher risk than men for thromboembolism in the setting of atrial fibrillation ( AF ). We investigated whether women with AF were at higher risk of ischemic stroke in the China-AF (China Atrial Fibrillation Registry) Study. Methods and Results A total of 19 515 patients were prospectively enrolled between August 2011 and December 2016 in the China- AF Study. After exclusion of patients receiving anticoagulation or ablation therapy, 6239 patients (2574 women) with results from at least 6 months of follow-up were used for the analysis. Cox proportional hazards models were performed to evaluate whether female sex was an independent risk factor for thromboembolism after multivariate adjustment. The primary outcome was the time to the first occurrence of ischemic stroke or systemic embolism. After a mean follow-up of 2.81±1.46 years, 152 female patients reached the primary outcome, as compared with 172 male patients. Crude incidence rates of thromboembolism between women and men were of borderline statistical significance (2.08 versus 1.68 per 100 patient-years, P=0.058). After multivariable analysis, female sex was not independently associated with an increased thromboembolism risk (hazard ratio 1.09, 95% confidence interval 0.86-1.39). There was no significant difference in thromboembolism risk by sex stratified by age and presence or absence of risk factors ( P for interaction all >0.1). Conclusions Although crude incidence rates of thromboembolism were higher in Chinese female patients with AF compared with male patients, female sex did not emerge as an independent risk factor for thromboembolism on multivariate analysis. Clinical Trial Registration URL : http://www.chictr.org.cn/ . Unique identifier: Chi CTR - OCH -13003729.

Long-term outcome of catheter ablation for atrial fibrillation in patients with apical hypertrophic cardiomyopathy.

INTRODUCTION: To assess the long-term outcome of catheter ablation in patients with hypertrophic cardiomyopathy (HCM), especially in patients with apical HCM (ApHCM). METHODS AND RESULTS: From 9,249 AF ablation cases, 97 patients (28 with ApHCM and 69 with non-ApHCM) were enrolled. Another 97 patients matched by age, AF type, AF duration, and left atrial diameter were selected as the control group. After a mean follow-up of (44.3 ± 29.6) months, success rate after a single procedure was 42.9% in the ApHCM patients (P  =  0.725), 36.2% in the non-ApHCM patients (P  =  0.136) versus 50.5% in the control group. After multiple procedures, success rate both in the ApHCM group (50%, P  =  0.047) and in the non-ApHCM group (50.4%, P  =  0.017) were lower than in the controls (68.0%). More patients in the ApHCM and in the non-ApHCM group suffered very late recurrence beyond 1 year after the index procedure. Left atrial diameter (hazard ratio [HR] 1.04, 95% confidential interval [CI] 1.01-1.08, P  =  0.018) and AF duration (HR 1.01, 95% CI 1.00-1.01, P  =  0.005) were independent predictors of recurrence after the index ablation. There was no difference in thromboembolic events between the HCM group and the control group (8.2% vs. 3.1%, P  =  0.082). CONCLUSIONS: Patients with ApHCM or non-ApHCM had similar success rate of AF ablation after single procedure and lower success rate after multiple procedure compared with the control group.

U-shaped association between serum free triiodothyronine and recurrence of atrial fibrillation after catheter ablation.

PURPOSE: Thyroid dysfunction affects the outcomes of atrial fibrillation (AF) catheter ablation. However, it remains unclear if the variations in thyroid function, especially in the triiodothyronine levels, are associated with AF recurrence in euthyroid subjects. This study investigated the associations of thyroid hormone levels with arrhythmia recurrence after AF catheter ablation in euthyroid patients. METHODS: A total of 1115 consecutive AF patients who underwent catheter ablation were prospectively enrolled and had their thyroid function measured prior to the procedure. The serum free triiodothyronine (FT3), free tetraiodothyronine (FT4), and thyroid-stimulating hormone (TSH) levels were assessed as predictors of recurrence and were adjusted for potential confounders. The subjects were divided into five quintile groups according to the FT3, FT4, and TSH levels, respectively. RESULTS: After a median follow-up of 723 days (interquartile range, 180-1070), 47.2% of patients experienced recurrence. After multivariate adjustment, subject in the lowest and highest FT3 quintiles showed increased risk of recurrence (hazard ratio [HR] 1.60, 95% confidence interval [CI] 1.26-2.03, P < 0.01, and HR 1.47, 95% CI 1.16-1.87, P < 0.01, respectively), compared to the median quintile of FT3 levels. Regarding the FT4 level, the highest quintile group showed a higher risk of recurrence (HR 1.27, 95% CI 1.01-1.60, P = 0.04). The TSH levels were not associated with AF recurrence. CONCLUSIONS: Both high and low FT3 levels were associated with AF recurrence after catheter ablation. High-normal FT4 levels were also related to AF recurrence; however, no association was found between normal TSH levels and AF recurrence.

Acute administration of tumour necrosis factor-α induces spontaneous calcium release via the reactive oxygen species pathway in atrial myocytes.

Aims: The arrhythmogenic mechanisms of atrial fibrillation (AF) that are induced by acute inflammation, such as postoperative AF, are not well understood. We investigated the acute effects of tumour necrosis factor-α (TNF-α) that mimic acute inflammation on Ca2+ handling in isolated atrial myocytes and its underlying mechanisms. Methods and results: Cytosol Ca2+ handling and mitochondrial reactive oxygen species (ROS) production were studied in freshly isolated atrial myocytes of wild-type mice that were exposed to TNF-α (0.05 ng/mL) for 2 h by Ionoptix and confocal microscopy. The acute effects of TNF-α on Ca2+ handling were decreased amplitudes and prolonged decay times of Ca2+ transients in isolated atrial myocytes. A significant reduction in the sarcoplasmic reticulum (SR) Ca2+ content was detected in TNF-α treated cells, which was associated with increased spontaneous Ca2+ release events. In particular, physiological concentrations of TNF-α dramatically promoted the frequency of spontaneous Ca2+ waves and Ca2+ sparks, while the spark mass presented with reduced amplitudes and prolonged durations. The underlying mechanisms of pro-arrhythmic effects of TNF-α were further investigated. Acute exposure to TNF-α rapidly promoted mitochondrial ROS production that was correlated with the acute effect of TNF-α on Ca2+ handling, and enhanced the oxidation of calcium/calmodulin-dependent protein kinase II (CaMKII) and the phosphorylation of RyR2. However, the performance of ROS inhibitor, DL-Dithiothreitol (DTT), reversed Ca2+ handling disorders induced by TNF-α. Conclusion: Tumour necrosis factor-α rapidly increases spontaneous Ca2+ release and promotes atrial arrhythmogenesis via the ROS pathway, which suggests that antioxidant therapy is a promising strategy for acute inflammation related AF.

Transseptal puncture and catheter ablation of atrial fibrillation in patients with atrial septal occluder: initial experience of a single centre.

Aims: Catheter ablation is underutilized in atrial septal defect (ASD) patients who have undergone implantation of an atrial septal occluder (ASO). This study evaluates the feasibility and safety of catheter ablation of atrial fibrillation (AF) in this subset of patients. Methods and results: Sixteen patients (age 56 ± 12 years, 10 men) with drug-refractory AF (10 paroxysmal and 6 persistent) and previously implanted ASO were enrolled. Balloon dilatation of the closure device was performed if the native septum passage could not be achieved. For paroxysmal AF, the ablation strategy was circumferential pulmonary vein isolation (CPVI), and for persistent AF, additional linear ablation was performed. Transseptal access was achieved through the native septum in 11 patients (Group A) and through the ASO using balloon dilatation in 5 patients (Group B). Circumferential pulmonary vein isolation was achieved in all 16 patients, and linear block was achieved in all persistent patients except for 1 patient who did not achieve mitral isthmus block. The transseptal, total fluoroscopy, and procedural durations were 5 ± 3 vs. 38 ± 8 min, 31 ± 11 vs. 54 ± 15 min, and 165 ± 35 vs. 224 ± 36 min, respectively, in Group A vs. Group B, respectively (all P < 0.05). No shunt at atrial level was detected by transthoracic echocardiography at 3-month follow-up. During a follow-up of 16 ± 6 months, sinus rhythm was maintained in 12 of 16 patients. No severe complications were observed. Conclusion: In ASD patients with ASO, catheter ablation of AF is feasible, safe, and effective. The balloon dilatation technique can facilitate transseptal access through the ASO.

Right atrial diameter and outcome of catheter ablation of atrial fibrillation.

PURPOSE: While AF is considered more like a left atrial (LA) disease, to what extent the right atrium contributes to the pathogenesis and ablation outcome of AF remains unclear. This study aimed to identify if right atrial diameter (RAD) could predict arrhythmia recurrence after catheter ablation of atrial fibrillation (AF). METHODS: Four hundred and seventy patients with drug-resistant AF [paroxysmal AF (PAF) 196; non-PAF 274] who underwent primary catheter ablation were enrolled. Ablation strategy included complete bilateral pulmonary vein isolation (PVI) in all patients and additional linear ablation across mitral isthmus, LA roof, and tricuspid isthmus in non-PAF cases. Risk factors associated with recurrence were determined by a Cox regression model, and the predictive power was evaluated by using receiver operating characteristic curve. RESULTS: After 24.3 ± 18.0 months, 284 patients (60.6%) experienced atrial tachyarrhythmia recurrence (111 in PAF, 173 in non-PAF). RAD was moderately associated with LA diameter (r = 0.371, P < 0.001), left ventricular ejection fraction (r = -0.205, P < 0.001), and left ventricular end-diastolic diameter (r = 0.319, P < 0.001). Multivariate Cox regression analysis demonstrated that RAD was an independent predictor for recurrence only in PAF patients with LAD ≥35 mm (HR 1.044, 95% CI 1.007-1.082, P = 0.021). The RAD cutoff value of 35.5 mm predicts atrial tachyarrhythmia recurrence with 85.4% sensitivity and 29.2% specificity. Kaplan-Meier analysis indicated that RAD over 35.5 mm is associated with more recurrence after PAF ablation (log-rank P = 0.034), comparing to those with RAD <35.5 mm. CONCLUSIONS: RAD predicts outcome of ablation only in patients with PAF and concurrent LA enlargement. Under this condition, RAD <35.5 mm is associated with a more favorable recurrence-free survival at over 2-year follow-up.

Over 1-year efficacy and safety of left atrial appendage occlusion versus novel oral anticoagulants for stroke prevention in atrial fibrillation: A systematic review and meta-analysis of randomized controlled trials and observational studies.

BACKGROUND: A direct comparison of the efficacy and safety profiles of left atrial appendage occlusion (LAAO) devices and novel oral anticoagulants (NOACs) for stroke prevention in atrial fibrillation is warranted but currently unavailable. OBJECTIVE: The aim of this study was to compare the >1-year efficacy and safety of LAAO devices and NOACs for stroke prevention in patients with atrial fibrillation. METHODS: We performed a systematic review on randomized controlled trials (RCTs) and observational studies. RCTs were analyzed by means of a network meta-analysis method using warfarin as a bridge to compare LAAO to individual NOAC or all NOACs as a whole. Observational studies were analyzed with the meta-proportion function where pooled event rates were compared. RESULTS: A total of 6 RCTs and 27 observational studies were included. A network meta-analysis of RCTs indicated that LAAO was less effective than NOACs for stroke prevention (odds ratio 0.86), but had a lower rate of hemorrhagic events during follow-up. However, a meta-proportion analysis of observational studies revealed that LAAO devices were associated with a lower rate of both thromboembolic events (1.8 events per 100 patient-years vs 2.4 events per 100 patient-years) and major bleeding events during follow-up (2.2 events per 100 patient-years vs 2.5 events per 100 patient-years) as compared with NOACs. With prolonged follow-up duration after LAAO implantation, the rate of thromboembolic events decreased (2.1, 1.8, and 1.0 events per 100 person-years for 1, 1-2, and >2 years, respectively). CONCLUSION: Although superiority of LAAO over NOACs was not demonstrated by RCTs in terms of stroke prevention, LAAO was found to be consistently associated with a lower rate of both thromboembolic and hemorrhagic events as compared with NOACs in observational studies.

Plasma galectin-3 predicts clinical outcomes after catheter ablation in persistent atrial fibrillation patients without structural heart disease.

AIMS: This study sought to explore the relationship between plasma galectin-3 (Gal-3) and persistent atrial fibrillation (PsAF), and investigate whether Gal-3 predicts clinical outcomes in patients with PsAF undergoing catheter ablation. METHODS: Fifty consecutive PsAF patients without coexisting structural heart disease undergoing first-time catheter ablation and 46 healthy controls were included. Blood samples were collected on admission for analysis of plasma Gal-3. Pre-ablation clinical and laboratory data were also recorded. Persistent atrial fibrillations patients were followed after ablation and AF recurrence was defined as episodes of AF or atrial tachycardia lasting >30 s after the blanking period. RESULTS: Plasma Gal-3 concentrations were higher in PsAF patients than in healthy controls (P < 0.001). In PsAF group, those with AF recurrence had higher plasma Gal-3 than did those without recurrence (P = 0.007). Both Gal-3 (hazard ratio 1.28, P = 0.006) and left atrial diameter (LAD) (hazard ratio 1.1, P = 0.025) were independent predictors of AF recurrence after ablation. Moreover, adding Gal-3 to LAD had an incremental predictive value for ablation outcomes (global χ(2) of LAD alone: 8.2; LAD and Gal-3 concentrations: 15.7; P = 0.006). CONCLUSION: Plasma Gal-3 concentrations are elevated in PsAF patients without structural heart disease and independently predict AF recurrence after ablation. Plasma Gal-3 concentration may be helpful in identifying appropriate candidates for AF ablation.

QTc Interval Prolongation Predicts Arrhythmia Recurrence After Catheter Ablation of Atrial Fibrillation in Patients With Hypertrophic Cardiomyopathy.

BACKGROUND: In hypertrophic cardiomyopathy (HCM) patients complicated with atrial fibrillation (AF), catheter ablation has been recommended as a treatment option. Meanwhile, prolongation of QTc interval has been linked to an increased AF incidence in the general population and to poor outcomes in HCM patients. However, whether QTc prolongation predicts arrhythmia recurrence after AF ablation in the HCM population remains unknown. METHODS AND RESULTS: Thirty-nine HCM patients undergoing primary AF ablation were enrolled. The ablation strategy included bilateral pulmonary vein isolation (PVI) for paroxysmal AF (n=27) and PVI plus left atrial roof, mitral isthmus and tricuspid isthmus linear ablations for persistent AF (n=12). Pre-procedural QTc was corrected by using the Bazett's formula. At a 14.8-month follow up, 23 patients experienced atrial tachyarrhythmia recurrence. Recurrent patients had longer QTc than non-recurrent patients (461.0±28.8 ms vs. 434.3±18.2 ms, P=0.002). QTc and left atrial diameter (LAD) were independent predictors of recurrence. The cut-off value of QTc 448 ms predicted arrhythmia recurrence with a sensitivity of 73.9% and a specificity of 81.2%. A combination of LAD and QTc (global chi-squared=13.209) was better than LAD alone (global chi-squared=6.888) or QTc alone (global chi-squared=8.977) in predicting arrhythmia recurrence after AF ablation in HCM patients. CONCLUSIONS: QTc prolongation is an independent predictor of arrhythmia recurrence in HCM patients undergoing AF ablation, and might be useful for identifying those patients likely to have a better outcome following the procedure.

Catheter ablation of atrial fibrillation in patients with rheumatoid arthritis.

BACKGROUND: Rheumatoid arthritis (RA) is associated with an increased incidence of atrial fibrillation (AF). This study evaluated the safety and efficacy of catheter ablation (CA) in the treatment of AF in patients with RA, which has not been previously reported. METHODS: A total of 15 RA patients with AF who underwent CA were enrolled. For each RA patient, we selected 4 individuals (control group, 60 patients in total) who presented for AF ablation in the absence of structural heart or systemic disease and matched the RA patients with same gender, age (±2 years), type of AF, and procedure date. RESULTS: Patients with RA had a significantly higher C-reactive protein level (1.81 ± 2.35 mg/dl vs. 4.14 ± 2.30 mg/dl, p=0.0320), white blood cell count (5632 ± 1200 mm(3) vs. 6361 ± 1567 mm(3), p=0.0482), and neutrophil count (3308 ± 973 mm(3) vs. 3949 ± 1461 mm(3), p=0.0441). At 2-year follow-up, atrial tachyarrhythmia (ATa) recurrence rate in the RA group (33.3%, 5/15) was similar to that in the control group (31.7%, 19/60; p=0.579) after single procedure. In all the five patients from the RA group who developed recurrence, ATa relapsed within 90 days following index procedure (median recurrence time 18 days vs. 92 days in control group; p=0.0373). Multivariate Cox regression analysis showed that hypertension and left atrial diameter but not RA, C-reactive protein, white blood cell count, and neutrophil count were independent predictors of ATa recurrence. CONCLUSIONS: Catheter ablation of AF can be safely performed in patients with RA, with a success rate comparable to that of patients without RA. RA patients tend to develop early ATa recurrence after AF ablation.